In the field of automobile design, convertible tops have been employed to provide the consumer with versatile styling. Most people are familiar with manual convertible tops, which are latched and lowered by hand. However, over the years, many different types of automatic and semi-automatic convertible tops have been developed. Generally, these convertible tops utilize one or more motors to move the various linkages and other movable elements from an extended (or top closed) position to a retracted (top open) position. Through the aid of motorized movement, the user can raise and lower the convertible top more easily.
However, simply providing for motorized movement of the convertible top is not enough. For example, there are known motorized convertible tops that provide for limit sensors on the elements to determine whether the elements are in the "full retracted" or "full extended" position. However, such systems provide no information as to whether the linkage elements are simply near, rather than being at, one of the two fully articulated positions or not. As a result, these known systems, while being capable of causing the convertible top to be opened and closed automatically, require each sensed element to reach an extreme position before commencing the movement of the next element in the sequence necessary to accomplish the desired movement of the convertible top. Thus, it would be advantageous if a motorized convertible top system could allow simultaneous movement of various elements so as to accomplish the opening and closing of the convertible top using a series of movements that are more fluid and continuous and that both reduce the time necessary to accomplish the movements as well as improving the aesthetic appearance of the movements.
Another disadvantage of known motorized convertible tops is the fact that the elements may bind as the movements are sequenced, increasing the load on the motors and risking damage to the motors or elements as the motors try to "force" the elements to move. Especially when trying to accomplish simultaneous movement of multiple elements, the fact that one element may be slightly inhibited in its movement means that the other moving elements will reach their desired position sooner than will the binding element. Allowed to continue uncorrected, this misalignment of elements can result in the convertible top being cocked in an undesirable position and may cause damage to the convertible top mechanism. Therefore, it would be desirable if there were some way to monitor the movement of critical elements while they are moving simultaneously so that remedial action can be taken in the event that a misalignment situation arises. The remedial action could include stopping the movement of other elements while the binding element is still moved, allowing the slower, binding element to "catch up" with the other elements. The remedial action could also include reversing the movement of some elements in order to realign the convertible top, and, once realignment is achieved, resuming normal movement of the elements. The remedial action could also include detecting an unrecoverable misalignment and shutting down the motors before the motors are overburdened.